The invention was developed with particular regard to a reinforcing device for earthworks, comprising at least one reinforcing base element from which a front wall extends, a containment wall extending from the reinforcing base element at a distance from the front wall in order to delimit at the rear, in an operative configuration in which the front wall and the containment wall are erected with respect to the reinforcing base element, a facing region which is to be filled with filling material, such as stones or the like.
In addition, the present invention was developed also with reference to a bifacial reinforcing unit for earthworks and to a method for the production of a reinforced earthwork having a facing composed of stones or the like.
It is known in the field to produce parallelepipedal wire netting gabions filled with stones and superposed on one another to form a soil-supporting structure in which the filling stones define a visible surface or facing.
One of the problems of the prior art is the high cost of installing gabions, which is caused above all by two factors. The first factor is the difficulty of obtaining stones of a suitable size, which often makes it necessary to transport them to the site concerned from long distances. The stones have to be of a size larger than the dimensions of the meshes of the netting used for the gabions in order to prevent them from falling out and therefore causing the facing to be emptied. The second cost factor is associated with the filling of the gabions with the stones, which has to be carried out manually in order to obtain an aesthetically acceptable visible face with a uniform distribution of the stones.
Also known are bifacial reinforcing units composed of a gabion which is assembled beforehand and superposed on a reinforcing base element in a manner suitable for guaranteeing the essential structural continuity. This leads to higher costs owing to the doubling of material in the bottom region of the gabion.
The object of the present invention is to solve the problems of the prior art and in particular to provide a reinforcing device and a bifacial reinforcing unit for earthworks and a method for producing earthworks which permit rapid and economical installation with minimum manual intervention, at the same time ensuring the production of aesthetic facings for the earthworks. A further object is to provide reinforcing devices and bifacial reinforcing units which are economical to produce, and to obtain a high degree of reliability and strength over time for the earthworks produced by means of the present invention.
In order to achieve the objects indicated above, the present invention relates to a reinforcing device for earthworks of the type indicated in the preamble of the present description, which comprises bracket means which can be coupled, in use, to the front wall and to the containment wall in order to maintain them in the operative configuration without constituting a substantial obstacle to the filling material of the facing region.
The advantage of such a device is the ability to fill the facing region between the front wall and the containment wall using mechanical means, for example, earth-moving machines, such as mechanical shovels. The material poured into the facing region by a shovel flows freely to occupy uniformly all of the available volume, not encountering obstacles on the part of the bracket means and thus accelerating the time taken to install the reinforcing device.
The bracket means may comprise one or more bracket members located in the facing region, each coupled, in use, to the front wall and to the containment wall. Preferably, the bracket members comprise quadrangular brackets with two opposing sides coupled to the front wall and to the containment wall, respectively, and one of the other sides located near the reinforcing base element. This feature affords the advantage of providing maximum stability and rigidity for the front wall and the containment wall during the filling operation, thus preventing them from being deformed by the pressure of the filling material.
The bracket members can therefore be produced using a metal rod, a metal section bar or the like. In that case, the bracket means are very economical and are easy to produce, which is why it is also possible to use a very large number of them, thus improving the rigidity of the reinforcing device.
According to a particularly advantageous embodiment of the invention, the reinforcing base element and the front wall comprise a first and a second netting structure, respectively, the meshes of the second netting structure being more closely packed than the meshes of the first netting structure.
It is therefore possible to reduce the dimensions of the filling materials, of the stones or the like, introduced into the facing region, thus making them easier to obtain and economical. The stones of a smaller size than those traditionally used for the manual filling of known gabions also facilitate the introduction thereof using the mechanical means and the uniform distribution thereof in the facing region, thus promoting the aesthetics thereof.
Preferably, the second netting structure of the front wall comprises a first wire netting having hexagonal meshes and a second wire netting having meshes which differ from those of the first wire netting. The second wire netting and the first wire netting are coupled to each other to give, as the overall result of the coupling thereof, the second netting structure having meshes that are more closely packed than the meshes of the first netting structure of the reinforcing base element.
Preferably, although this does not constitute a limitation, the second wire netting is a netting having square meshes, for example of the electrically welded type.
The first wire netting of the front wall and the netting structure of the reinforcing base element may advantageously be folded portions of a single wire netting.
The containment wall of the present invention may advantageously be covered with a geotextile material in order to prevent any fine materials in contact with the containment wall outside the facing region from penetrating into the spaces between the filling stones of the facing.
The objects indicated above are also achieved by a bifacial reinforcing unit for earthworks which comprises a reinforcing device of the type indicated above with the addition of a second front wall which extends from the reinforcing base element on a side opposite the first front wall of the reinforcing device.
The main advantage deriving from the use of such a reinforcing unit to produce works having a central core of reinforced earth and two opposing lateral facings is the speed and economy of installation, to which is added the economical nature of the production of the unit which is due to the saving of material, compared with known units, in the production of the reinforcing base element.
A preferred method for achieving the objects indicated and producing a reinforced earthwork having a facing of stones or the like comprises the stages of laying down the reinforcing base element of a reinforcing device according to the present invention, erecting the front wall and the containment wall, holding them erect and spaced in the operative condition using the bracket means, filling the facing region delimited by the front wall and the containment wall with a first filling material, such as stones or the like, having dimensions substantially larger than the dimensions of the meshes of the front wall in order to form a portion of stone facing, filling and levelling with a second, different, filling material, such as earth, sand, crushed stone or the like and their combinations, the region affected by the reinforcing base element, which region is outside the facing region, to a height substantially equal to the height of the front wall and the containment wall, and repeating the previous stages, superposing on one another in succession a predetermined number of reinforcing devices until the desired height of the reinforced earthwork is reached.
Preferably, the filling of the facing region is carried out using the mechanical means already mentioned in order to benefit from the reduced installation times which result therefrom, and therefore to benefit from the lower production costs.
If a bifacial reinforcing unit of the type described above is used, the method also comprises, for each repetition, the formation of a second portion of a second facing at the location of the second front wall, which preferably permits subsequent re-growth of vegetation on the second facing. In that case, it is particularly advantageous from the aesthetic and practical point of view to incline each second front wall of each reinforcing unit with respect to the reinforcing base element by a predetermined angle, and to produce the reinforcing base element of each subsequently superposed reinforcing unit with smaller dimensions than that of the reinforcing unit underneath in order to produce the second facing which is inclined overall.